(Figs. 19a–d)
[Key locator: Key to Group B species, couplet 21 (20)]
Heteragrion calafatiensis: Mendoza-Penagos et al. 2022: 223–229 (description of ♁ from Pará state, Brazil; diagnosis and comparison with H. chlorotaeniatum; figs. 1, 2a–d).
Material examined. 1♁ (HOLOTYPE) BRAZIL, Pará, Magalhães Barata, way to Calafate village, near to the Marapanim River, 26.ix.2021, (-0.8632, -47.6680, 20m asl), C.C. Mendoza-Penagos leg., UFPA.
Known distribution. Brazil (Northeastern Pará state).
Diagnosis and remarks. This newly described species, known only from the male holotype (Mendoza-Penagos et al. 2022), can be separated from the remainder of Group B species by the following character combination: BP with a nearly straight margin (Fig. 19c); MP the shortest portion of cercus in length (Fig. 19c); Ridge above ML upcurved, not very long (Fig. 19c); MP–AP junction forming a nearly straight line with AP (Fig. 19c); in lateral view, ML bent downwards (Fig. 19d); ML apex rounded (Fig. 19c).